1. Field of the Invention
The field of this invention relates to apparatuses that facilitate the movement of heavy structures and more particularly to a low frictional transfer apparatus that is to be incorporated in conjunction with the operating surface of a table on which the heavy object is designed to rest.
2. Description of the Related Art
Forming machines, such as punching and stamping machines, have a table on which is to be located a workpiece. It is common for these tables, which are frequently referred to as a bolster, to have a planar operating surface which is the upper surface of the table. The workpiece is to be placed on this operating surface.
It is typical that workpieces weigh several hundred pounds. The workpiece will always have to be adjusted in position on the table until the workpiece is in a precisely located position on the table at which time the workpiece is locked in position and then the parts that are to be produced utilizing of the workpiece are then produced. In the past, it has been typical that the movement of the workpiece is accomplished manually or by power by the machine operator. This means that the operator will physically press against the workpiece in order to get the workpiece to move an inch, one-half inch, an eighth of an inch or whatever. The moving of a workpiece that weighs several hundred to thousands of pounds is not easily accomplished by such manual or powered movement. Small movements are produced by a tool known as a die bar.
Typically, workpieces are also transported within machine shops to the bolster of a punching and stamping machine by means of a cart. The workpiece is placed on the cart and the cart is rolled to a position directly adjacent the bolster and the workpiece is then moved from the cart onto the operating surface of the bolster. The cart includes a table on which the workpiece is located. Again, manual movement is required to get the workpiece to move from the cart to the bolster. It would be desirable to incorporate some type of a low frictional transfer apparatus in conjunction within tables of carts and in conjunction with bolsters of punching and stamping machines and in conjunction with tables of any type of a forming machine that would make it substantially easier to manually move a heavy workpiece.
In combination with a table for supporting a workpiece, a low frictional transfer apparatus for permitting ease of movement of the workpiece across an operating surface of the table. Incorporated within the table are a plurality of spaced apart slots. A rail member is to be mounted within at least two in number of the slots with there being a separate rail member within each slot. Each rail member has a plurality of rolling members protruding from its upper surface. Each rail member includes a plurality of pistons capable of extending from its lower surface. The pistons include footpads. The footpads are extendable from the lower surface of the rail member by the application of pressurized air to the pistons which will then cause the rolling members to be raised above the working surface of the table with the workpiece resting solely on these rolling members. The rolling members permit easy movement of the workpiece on the working surface.
A further embodiment of the present invention is where the main embodiment is modified by the slots being defined as being straight.
A further embodiment of the present invention is where the main embodiment is modified by the slots being defined as parallel.
A further embodiment of the present invention is where the main embodiment is modified by the slots being defined as having an upside down T-shape cross-sectional configuration.
A further embodiment of the present invention is where the main embodiment is modified by the rolling members being defined as being balls.
A further embodiment of the present invention is where the main embodiment is modified by the piston assembly comprising a plurality of pistons that are mounted in a spaced apart arrangement within each rail member. Each piston is movably mounted within a cylinder with there being a separate cylinder for each piston. A connecting passage connects between directly adjacent pairs of cylinders. The air pressure to be supplied to the cylinders being permitted to flow through these connecting passages.
A further embodiment of the present invention is where the main embodiment is modified by each rolling member being mounted within a housing. There is mounted a spring between the housing and the rail member to provide a resilient slightly deflectable support for the rolling members when the weight of the workpiece is applied to the rolling members.
A further embodiment of the present invention is where the just previous embodiment is modified by each piston being movably mounted within a cylinder with there being a separate cylinder for each piston. A connecting passage connects between directly adjacent pairs of the cylinders with the air pressure to be supplied to each cylinder by being permitted to flow through these connecting passages.
A further embodiment of the present invention is where the just previous embodiment is modified by the rolling members being defined as balls.
A further embodiment of the present invention is where the just previous embodiment is modified by the slot in transverse cross-section having an upside down T-shape.
A further embodiment of the present invention is where the just previous embodiment is modified by the slots being defined as parallel.
A further embodiment of the present invention is where the just previous embodiment is modified by the slots being defined as being straight.